Elsevier

Veterinary Parasitology

Volume 165, Issues 3–4, 12 November 2009, Pages 341-344
Veterinary Parasitology

Short communication
Fasciola hepatica infections in livestock flock, guanacos and coypus in two wildlife reserves in Argentina

https://doi.org/10.1016/j.vetpar.2009.07.011Get rights and content

Abstract

Between autumn and spring 2006, a coprological survey was performed in two wildlife reserves located in the north of Argentine Patagonia to determine the prevalence of Fasciola hepatica and the number of parasite eggs per gram (epg) of feces in wild guanacos (Lama guanicoe), coypus (Myocastor coypus), and locally born and raised goats and sheep. Snails of the Family Lymnaeidae were collected in freshwater habitats, identified taxonomically and analyzed parasitologically.

Prevalence of patent infection was 100% in sheep (n = 69) and coypus (n = 9), 84% in goats (n = 20) and 0.5% in guanacos (n = 224). No significant differences in epg were found among animals, but the median epg of coypus (160) and sheep (160) was higher than that of goats (80). For guanacos and goats, a negative binomial model estimating the population egg-count frequency could be fitted, while for coypus and sheep parasite egg-count frequencies trended toward a normal distribution, indicative of a more even, and much less aggregated distribution across sampled hosts. All snails (n = 175) were Lymnaea truncatula and none of them was found infected. This is the first report of fascioliasis in free-ranging guanacos in Argentina. Coypu appears to be a major wildlife reservoir of F. hepatica, which was presumably introduced locally by livestock.

Introduction

Fasciola hepatica, the liver fluke, has an indirect life cycle involving domestic and wild herbivorous mammals and humans as definitive hosts, and freshwater gastropods of the Family Lymnaeidae as intermediate hosts (Andrews, 1999). Infections with this parasite give rise to a cosmopolitan zoonotic disease, fascioliasis, which is a food-borne trematodiasis (Torgerson and Claxton, 1999). In farmed livestock the disease causes important economic losses due to liver condemnation, decreased meat, milk and wool production and increased mortality (Dargie, 1987).

In Argentina, fascioliasis is of concern in farmed livestock. Liver condemnation rates at abattoirs can be nearly 80%, with highest values reported for cattle from Patagonia (Kleiman et al., 2007). In this region detailed epidemiological surveys involving both definitive and intermediate hosts have been performed in cattle ranches (Kleiman et al., 2005, Kleiman et al., 2007, Rubel et al., 2005), but as yet there is no information concerning fascioliasis in natural protected areas where animals may, or may not, become infected and play a local role in transmission.

In South America F. hepatica has been reported in two large rodent species: the coypu or false nutria (Myocaster coypus) in Argentina, and the capybara (Hydrochoerus capybara) in Venezuela (cited in Sutton, 1989). South American camelids, e.g. alpacas (Lama pacos) and llamas (Lama glama), are known to be highly susceptible to fascioliasis but generally observed prevalence is low (∼8%) inasmuch as mortality in severe acute infections can be 100% (Leguía, 1991).

In this paper, we report the findings of an epidemiological survey in two wildlife reserves in Argentina and document for the first time active transmission foci of F. hepatica and infection in wildlife.

Section snippets

Material and methods

The study area comprised the Natural Reserves of La Payunia (36°00′S, 68°34′W) and Laguna de Llancanelo (35°45′S, 69°08′W), both located in the Department of Malargüe, Province of Mendoza, northern Patagonia, Argentina. The La Payunia Reserve occupies 450,000 Ha and hosts the largest (about 10,000 heads) wild guanaco (Lama guanicoe) population in the country (Candiar et al., 1993). This camelid has experienced a dramatic population decline in the last 50 years due to severe hunting pressure (

Results

The prevalences and median epg values for the different herbivores analyzed are shown in the Table 1. The Chi-square test revealed significantly different prevalences among sheep, goats, coypus and guanacos (Chi-square = 270, p < 0.05). Further analysis indicated that there were no significant differences in the prevalence of sheep, goats and coypus (Chi-square = 2.6, p < 0.05) while the prevalence of guanacos was significantly lower than those of the remaining herbivores (Chi-square = 267, p < 0.05). The

Discussion

The occurrence of active F. hepatica transmission foci in the reserves of Payunia and LLancanelo was confirmed by the simultaneous presence of L. truncatula snails and infected livestock and wild animals. The reserves appear as areas of very high transmission based on the high prevalences and egg counts obtained from livestock. The occurrence of foci is further favored by the limited availability of water as a resource. Both sheep and goats are very susceptible to F. hepatica, have no

Acknowledgements

We thank the park ranger of Payunia Reserve Mr. Anibal Soto for field assistance. This study was supported by the Universidad de Buenos Aires (Project no. X-246, 2004–2008).

References (33)

  • M.M. Cafrune et al.

    Fasciolosis en vicuñas (Vicugna vicugna) en semi-cautiverio de Molinos, Salta, Argentina, con notas de otros helmintos en este hospedador

    Vet. Arg.

    (2004)
  • R. Candiar et al.

    Diseño del plan de manejo para la Reserva Provincial La Payunia (Malargüe, Mendoza)

    Multequina

    (1993)
  • A. Ciprian

    Determinación del grado de lesión con respecto al grado de infección causada por distomatosis hepática en alpacas de Ayacucho

    (2007)
  • J.P. Duff et al.

    Chronic and fatal fasciolosis in llamas in the UK

    Vet. Rec.

    (1999)
  • L. Issia et al.

    Galba truncatula Muller, 1774 (Pulmonate: Lymnaeidae) in Argentina: Presence and Natural Infection by Fasciola hepatica (Linnaeus, 1758) (Trematoda: Digenea)

    Veliger

    (2008)
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